Healthy buildings

Ideally your home should be the place where you are best protected from the woes of the world, from pollution and all the nasties out there. But it’s not so for most people.

The concept of ‘sick building syndrome’ has now moved from speculation into widespread acceptance with several well designed studies showing how people can react badly towards certain aspects of poorly designed buildings. This subject has several partly overlapping areas

air quality

problems associated with dampness

microbe allergens

poor ventilation

chemical pollution

pollution from building materials

pollution from household products (not covered here)

light quality

electromagnetic radiation

What makes it all quite interesting are a number of interrelated factors which have emerged over the last two or three decades –

we spend, on average, nearly 90% of our time indoors so the quality of indoor air is crucial

there has been a massive rise in the number of building, decorating and furnishing materials which are likely to emit VOCsVolatile organic compounds. Almost every internal surface of the average room is plastic coated or made of some type of plastic. This includes wood particle boards, paints, varnishes, floor coverings etc. There is very often only glass and maybe a stainless steel sink which escapes. Most of these plastics give off VOCs, particularly when they are new. Formaldehyde, which is widely used as an adhesive offgases from many building materials.

Indoor air quality is now generally worse than outdoor.

Incidence of asthma and other respiratory diseases which can be triggered by poor air quality have been rising rapidly

it has become important to carefully control ventilation to reduce energy usage (and hence CO2Carbon dioxide is a gas which is given off when carbon based materials such as fossil fuels (coal, oil, and natural gas) are burned. It is called a greenhouse gas because it works like the glazing of a greenhouse and causes global warming emissions)

What studies regularly show is the interrelationship between air quality, moisture (or dampness) levels, insulation, ventilation and energy use. This is where the PassivhausSee more on the Passivhaus standard. The PassivHaus Institute has pioneered a standard for low energy buildings. It includes very low energy usage and ways of achieving this. The word is derived from the idea of buildings which are fundamentally low energy and passive solar heated rather than using extra gadgets to heat them. See Passivhaus for the UK branch of the organisation. standard is particularly effective provided care is taken with the low toxicity of the materials

The reasoning with Passivhaus goes –

Reduce energy use by massive insulation and careful ventilation. By getting this right not only is central heating not needed but internal surfaces never fall below their dew pointWarm air contains (invisible) water vapour. If you cool the air down you will reach a point where this vapour turns to liquid water. This is called the dew point. so internal condensation (and consequent fungal growth) cannot form. Carefully distributed ventilation ensures high air quality.

Quality standards for building materials

There are various standards by which to judge green building materials but the UK has not signed up to any standard (except indirectly through the EU – see the comprehensive REACH legislation) and seems to prefer to bandy the term ‘natural’ around as if it was the way to judge quality. (remember that sunlight is natural and can give you skin cancer whereas sun block cream is an artificial chemical and might save your life).

Some of the standards in European countries are –

IBO – the Austrian Institute for Healthy and Ecological Building. This was one of the first labels and is now considered one of the most difficult for a product to achieve

The Blue angel in Germany

The Swan eco label in the Nordic countries (based in Finland)

The European Eco label (run from England)

Nature Plus is an international label based in Germany

The Dutch Eco-label – Milieukeur

A thorough analysis of the way forward with natural building materials is the book ‘Low Impact Building’.

Light Quality

While most people do not notice the high frequency flicker from fluorescent lamps (not the flicker when a tube is failing but the slight 50hz flicker they always emit) a significant percentage of people react badly and in some cases it can cause a reaction like epilepsy. The way to correct this is to use high frequency luminaires which operate at 47,000hz instead of 50hz. This completely avoids visible flicker. Although the fittings are dearer there are 5 other advantages

they are more efficient

they last longer

they are dimmable

they come straight on rather than flickering first

and they work at full power till they fail (rather than dropping of in performance)